Application of a stochastic version of the restoring force surface method to identify a Duffing oscillator

International audienceThis work deals with the identification of stochastic parameters in a nonlinear single degree-of-freedom system. For this purpose, a stochastic version of the restoring force surface method is proposed and used to identify the parameters of a clamped-free beam, with nonlinear effects induced by the presence of a magnet near to the free extremity. This system recalls a Duffing oscillator, which is used as mechanical-mathematical model. In order to validate the obtained stochastic model, experimental and theoretical responses are compared in time and frequency domains, taking into account a probabilistic band of confidence. The results show that obtained stochastic model adequately predict the beam's vibration responses, which ensure the robustness of identification of a stochastic model